Effect of Fly Ash Contents on the Durability and Mechanical Properties of Recycled Fine Aggregate High Ductility Cementitious Composites

The effects of various fly ash (FA) contents on the durability and mechanical properties of recycled fine aggregate high ductility cementitious composites (RFA-HDCC) prepared with recycled fine aggregates (RFA) to fully replace natural fine aggregates was investigated. The results indicated that a 50% FA content significantly increased the compressive strength of RFA-HDCC by 13.93%. However, a further increase in FA content led to a drastic decrease. The increased fly ash content substantially reduced the flexural and tensile strength; however, it markedly increased the matrix strain capacity, resulting in a 53.73% increase in the peak strain when FA was raised to 70%. Regarding durability, the increase in FA content negatively affected the chloride ion permeability and carbonation resistance. However, the increase in FA content initially improved the frost resistance of RFA-HDCC, peaking at 50% FA and deteriorating at 60% and 70% FA content.